There is no "Break at point" command in AutoCAD and as you are using AutoCAD LT, you can not use AutoLISP routine to create new command for that. The only one option in LT is to use macro assigned to the button on Tool Sets palette or to menu item.
On the other hand you can try to use shortcut assignment to the menu item as in Mac OS shortcut assignment is a feature built in OS.
So, add "Break at point" command to the menu using CUI command in AutoCAD, than go to MacOS System Preferences (Keyboard pane) and on Shortcuts tab assign some shortcut to "Break at point" menu item in AutoCAD LT application.
Now you can use new shortcut in AutoCAD to call "Break at point" macro.

Maxim